Stem cells treat brain disease

10th November 2009

In the two year anniversary of a landmark medical victory, scientists in France appear to have successfully used gene therapy to halt the development of a deadly brain disease in two pre-adolescent boys.

For the purposes of fighting the disease, the researchers used a mixture of bone marrow transplantation and gene therapy.

Head researcher Patrick Aubourg of the University Paris-Descartes said that it was the first time researchers had used gene therapy against a severe brain disease.

Kenneth Cornetta, president of the American Society of Gene and Cell Therapy, said that the French study showed the power of combining gene therapy and cell therapy.

The disease, adrenoleukodystrophy or ALD, was once depicted in a movie known as "Lorenzo's Oil."

It can destroy the myelin sheath that coats nerve fibres in boys' brains.

The disease arises in boys between the age of four and 10, killing within a few years and crippling the child with blindness, dementia, deafness, and loss of muscle control.

A successful bone marrow transplant can halt the progress of the disease.

However, it is rare that sufferers can find an appropriate bone marrow donor, and a successful bone marrow transplant is a rare occurrence.

The researchers proceeded to reconstruct stem cells from the bone marrow of two other boys in the early stages of ALD.

However, they had no way of proliferating the reconstructed stem cells within the boys' bodies in order to cure the disease.

In gene therapy, scientists usually use viruses to proliferate the new gene throughout the body of the sufferer but, in this case, there was no previously used virus that would work.

But when the research team realised that HIV might work in order to deliver the therapy, they performed operations on the virus that left it ineffective against humans.

In the first ever achievement of its kind, the French scientists used the structure of HIV to deliver treatment to the two preadolescent boys.

Aubourg said that it had been two years since treatment, and the boys' conditions had not shown any sign of worsening.

Theodore Friedmann of The University of California in San Diego in the US said that the French scientists' work was a major achievement, and that gene therapy deserved to be seen as a new form of medicine.

He said that this was the fifth disease in which researchers had shown could benefit from gene therapy.